The present invention relates to a method and a device for controlling a production unit of a production installation. Said production installation is, in particular, a production and packaging installation, preferably one for cigarettes or other articles for smoking. Such an installation comprises a number of different production units, which however are combined with one another in the production and packaging process, for example a cigarette production machine (maker), a packaging machine (packer), a film-wrapping machine, and, if appropriate, a multipacker and a carton packer. The speeds within the individual production units are coordinated in respect of a speed of a central drive of the respective production unit, also referred to as master drive or master shaft. The speeds of all other drives (slave drives) of the production unit are derived from the speed of the master shaft.
For servicing, it is necessary to gain access into the production installation or into an individual production unit. During such access, the installation or the production unit is in principle shut down. However, it may be necessary that the installation or production unit, hereinafter referred to jointly as installation, is started up again at a controlled speed during the service work, for example to permit access also to otherwise concealed sections of individual units, for example a section of a revolver in the area of the film-wrapping machine. This has hitherto been achieved by the installation or a central part of the installation being covered by a protective arrangement, for example in the form of a hood. To gain access into the installation, the hood has to be opened. When the hood is opened, the installation shuts down. The master shaft can now be turned further using a handwheel. The speed of rotation thus set for the master shaft influences the speeds of rotation of the dependent drives. Even with a comparatively low speed of rotation of the master shaft, it is possible for there to be a high speed of rotation of individual dependent drives. For this reason, all the dependent drives are safeguarded by in each case a further hood, as it were a “hood within a hood”. When a hood of a dependent drive is opened, further movement of the master shaft is blocked.